The following generally relates to positioning, and more specifically, but not by way of limitation, to indoor position determination of a mobile device.
Current smart phones feature a rich set of sensors and include GPS receivers. The ability to sense the phone's environment and its position has enabled a multitude of context-aware and Location Based Services (LBS). However, in the future, users may desire expanded abilities to gather knowledge from their surroundings, interact with a variety of consumer electronic devices, and obtain accurate location information, both outdoors and indoors.
In the past few years, indoor positioning has received a great deal of attention both from the research community and the industry. Systems that use signals transmitted by Wi-Fi routers or cellular towers may leverage existing infrastructures. But they may rely on networks that are not designed to support positioning; therefore, they may not be easy to expand and often can only provide coarse resolution unless they are calibrated using extensive measurement campaigns. Ultra-Wide Band (UWB) systems based on Time Difference of Arrival (TDoA) provide high accuracy, but may entail the use of expensive infrastructures.
As noted, solutions typically propose the use of reference devices. Position determination may be performed by collecting measurements from such reference devices (e.g., routers). These devices may be required to work continuously, and their positions accurately known to the system. Some types of reference devices are not permanently anchored, and there may be challenges to “self-localize” the position of these devices. In many cases, the location of each reference device may be manually annotated at deployment time. Clearly, this approach can be time-consuming and prone to errors. Additionally, there is the potential that some of the reference devices may be unplugged or replaced due to maintenance and plugged in in undesired locations. There may, therefore, be a need in the art to address one or more of the above issues with novel techniques for position determination.